Compressor piston



Feb. l 1927.

G. F. KNOX coMPREssoR PISTON Filed Jan. 10, 1922 R .Y w W m m W41/ A H V atent Feb. ll, 1927r GEORGE r. Krtox, Or' mtwaoxnn, WIsOONsIN, AssrGNOR 'ro KNox Rnrmonnarrou OO., Or Mmwaunnn, Wisconsin, A CORPORATION OF' WIsOONsIN.

COMPRESSOR JPISTON.

application med January 10; 1822. o serial No. 528,858.

This inventin relates to 'improvements in valve structures for compressorsfor the like. One of the 'objects of the invention is to provide a valve structure'of such constructon that the valves have a very small amount of movement relative totheir seats, consequently, reducing wear of the valves to a minimum, and which permits the structure to be operated at a relatively high speed With a minimum amount of noise. i

A further object of the invention is to provide a valve structure of such construction that the parts thereof may bc easily and conveniently assembled, removed and replaced in case the parts become worn, corroded, or eaten away'by the gases to such an extent as to require replacing. w

A more specific 'object of the invention 1s to provide a novel valve' structure in whicx the cylinder head, which may be either of the fixed or yielda'ble type, is provided with one or more annular laterally extending flanges to forma seat for anannular flat valve, the cylinder head also being provided with an annular depending flange terminating over thevalve to limit upward movement thereof.

Another and more specific object of the invention is to provide a novel check valve in the piston head, the piston on its working side being provided with an annular recess which is adapted to receive an annular depending flange carried by the check valve, means being provided also to limit movement of the check valve relative to the piston head.

A further object of the invetion is to provide a two-part piston head of such conlstruction that one part constitutes a valve normally rigid in relation to the other part, but which will yiel'd should thepiston en- 'counter an obstruction on its return stroke, for example, an accumulation of water. The invention consists in the novel constructions, arrangements' and devices to be hereinafter described and clairned for carrying out th'e above stated objects and such other obj ects as will appear from the followin description of a certain preferred emboiment illustrated in the accompanying drawings, wherein- Fig. 1 is a Vertical sectional view of a fragmentary portion of a compressor, embodying the principles of the nvention; and

-flange 19 formed On the cy inder head and Figi. 2 is a sectional view taken on the line 2-2 of Fig; 1.

Like charactersof reference designate like parts in both views. Q

Referring to the (lrawings, it will be scen that the invention is illustrated as embodied in a compressor having a piston, designated generally by the reference character 5, workw .iug in a cylinder' G'provided with a head 7, the head v7 preferably being of thev yieldable type and normally held against the annular shoulder 8 of the cylinder vby a relatively stifi` spring 9. i

In .the preferred form of the'invention, the cylinder head includes a bot-tom portionv 10 provided with an annula'r outwardly extending- 'flange portion 11, the portion 10 being secured to the cylinder head by a threaded stud 12. The cylinder head also is provided with an annular Vertically positioned ring 13, the upper side of' which is positioned against the under side of the cylinder head, the `ring being secured there- 'to by a plurality of screws 14. The ring 13 is provided with a plurality of apertures 15 for the passage of the gases being compressed and with an inwardly extending portion 16 Vwhich is concentric with and spaced from the portion 11, the portions 11 and 1G forming a seat for an annular fiat fioating valve 17. Circumferential movement of the yalve 17 relative to its seatds prevented by a pin 18 which extends through an aperture in the valve 17 and into the seat portion 11. Upward movement of the valve 17 relative to its seat is limited by a de ending annular terminating over the valve 17. In order to retard or cushion the closing of the valve 17 a plurality of recesses 20 are provided in the under side of the flange 19, these recesses acting as dashpots, as will readily be apparent. The piston 5 comprises a lower portion 5a rigidly secured on the piston Stern 21 by a'nut 22and an upper portion 5'J mounted on the upper end ofthe stem and which is provided with an annularl recess 23 in which is'positioned a relatively stf spring 24, the stem carrying a nut 25 adapted to bear on Said spring to hold the portion 5b normally against a seat 2G formed On the stem. The part 5a is provided with a tapered seat 27 for the annular Valve 28 formed on the part 5b. A vplurality of vertically extending grooves 29 are formed in the periphery of the part 5b to provide for a freer passage of the gases between the parts 5a and 5b.

The portion 5b of the piston is provided on its Working side with 'an annular recess 30, the lower portion being provided with a plurality of passageways 31 so that the gases to be compressed may freely pass upwardly through the head. An annular flat check valve 32 is positioned over the recess 30 and is provided with an annular depending fiange portion 33 which extends into said recess. The flange 33 bears against an annular perforated ring 34; carried by the part 5 thereby preventing relative lateral movement of the valve32 on its seat. The portion 33 is provided with an outwardly latei'ally extending flange 85 adapted to bear against the under side of the ring 34 to limit upward movement of the valve 32 relative to its seat. The ring 34 is adjustable, being lockcd in the desired position by a set screw 36, whereby the amount of travel of the valve 32 may be regulated, as desired.

It will be apparent from the foregoing description that the movement of the valves 17 and 32 need only be very slight, cons'equently the wear of the valves and their seats is reduced to a minimum. The valve structure may be operated at a relatively high speed with practically no noise because of the small amount of travel of the valves. Ordinarily there is no movement of the part 5b of the piston relative to the part 5a. Should the piston encounter water or the like in the bottom of the cylinder on its return stroke the part 5b will yield, that is to say, move upwardly relative to the part 5*3 and permit the trapped fluid to escape between the valve 28 and its seat 27 thus relieving the. valve 32 and its associated parts of any undue strain.-

over said recess, an annular fiange portion depending into said recess from said flat portion, and an annular ring carried by the piston and co-operating With said depending flange portion for the purpose described.

2. A piston having an annular recess` formed in its Working side, passageways extending *from the opposite side of saidl piston into said recess, a check valve con'lprising an annular flat portion adapted to be positioned over said recess, an annular fiange portion depending into said recess from said flat portion, an annular adjustable ring carried by the piston and co-operating with said depending fiange portion, and means to prevent movement of said ring relative to said piston. i i

8. piston having an' annular recess formed in its working side, passageways cxtending from the opposite side of said piston into said recess, a check valve comprising an annular flat portion adaptcd to be positioned over said recess, a flange formcd centrally of said annular flat portion, and extonding into said recess, a laterally extending flange :formed on the free end of said first mentioned flange, and adjustable means cooperating With said laterally cxtending GEORGE F. KNOX. 

